1. FIELD OF THE INVENTION
This invention pertains to a conveyor type oven having an insulated shell and a fan for moving a flow of cooling air between the insulation and the exterior shell; the invention also pertains to an inlet door, outlet door and single drive motor for both the fan and a conveyor within the oven.
2. PRIOR ART
The prior art ovens are typically operable in a temperature range of 225.degree. to 500.degree. F. When and if these ovens are operated at higher temperatures, critical external areas of the oven become too hot to touch. Examples of these critical areas are the access doors. A human can touch 140.degree. F. without being burned or scalded, but anything over that temperature will at least be objectionally uncomfortable and probably of a temperature which can cause injury.
Another disadvantage of the prior oven is that it typically has an insulated access door. This access door usually has an inner shell, an outer shell and a layer of insulation between the shells. The periphery of the outer shell gets objectionably hot and when the access door is open, the very hot inner door is presented to the oven operator who will be burned if he or she touches the door inner shell.
The prior conveyor oven uses one motor to power the conveyor and if cooling is required by the oven, a complete additional cooling device must be installed. All conveyor mechanisms are believed to be subject to jamming, even if they are of a perfectly 100% reliable design, because an operator using the conveyor may place something upon the conveyor that will not work and if the conveyor jams, provision must be made to prevent structural damage to the conveyor.